feed.html

{% for user_item in user_items %}
    <div class="item">
        {% include "item.html" with item=user_item.item %}
    </div>
    <div class="actions">
        <form action="{% url "mark_read" user_item_id=user_item.id %}" method="post">
            <button>Mark as read</button>
        </form>
    </div>
{% endfor %}

views.py

def feed(request):
    user_items = UserItem.objects.filter(user=request.user)
    return render(request, 'feed.html', {user_items: user_items})


def mark_read(request, user_item_id):
    user_item = get_object_or_404(UserItem, user=request.user, id=user_item_id)
    user_item.read = True
    user_item.save()
    return redirect(feed)